bostw-ick



@uitrit 'tzttcs dntent @ffice S. A. BSTWI-CK, OF LACONIA, NEW HAMPSHIRE. Letters Patent No. 72,159, dated December 17, 1867.

' IMPROVEMENT IN PLUMES AND LEVELS.

TO ALL WHOM IT MAY CONCERN Be it known that I, S. A. BOSTWICK, of Laconia, in the count-y of Belknap, and State of New Hampshire, have invented an Improved Plumb and Level; a-nd I do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings, making part of' this specification.

Figure 1 being,r a left side view of the instrument.

Figure 2, a front edge view thereof.

Figure 3, a right side view of' the same, showing the stock in different positions for plumbing, levelling, and determining inclinations.

Like letters designate corresponding parts in all of' the figures.

In one edge of the stock A` of the level, is formed a sexnicircular space, in which fits a semicirculnr spiritbloek, B, which contains the spirit-vial or tube D; This block hns a turning movement in the concave space, :t quarter of a circle, so that it may be moved froma vertical position parallel with the stock, ns in fig. 1, to a. horizontal position at right angles to the stock, as indicated by the block B; (represented in black 1ines,) in relation to the vertical position of the stock, as indicated by red lines in fig. 3. nd it may, of course, have any intermediate angle or inclination between these two positions, as indicated by the relation of the block to the stock in blue lines, in the said fig. The block is guided in its movements by semicircular `.grooves in its surfaces, as shown :1t g, (fig. 2,) and at z', (fig. 3,) into which grooves studs o1' screws Li/L and ZZ project in through the plates or mountings a substantially as represented. These'studs or screws also act as stops, to limit tlie movement of the block, at the parallel position in one direction, and at the right-angled position in the other direction, those grooves being ciosed at the ends, so as to'act as n limit in connection with the stops. The block is adjusted to and confined in any position required, by means of a thumb-screw, C, reaching in through a nearly semicireular slot, G, in one of the nwur1ting-plates b of the stock, intoa projection of' the block, serving as a nut to tighten the thumb-screw. A seele or protrnctoigf, on the mountingplate, marked with the degrees of the quadrant, indicates the angleof' the stock at any time. In iig. 3, the block B is`represented as level, while the stock A is shown in red lines for plumbing, black lines for levelling, and blue lines for determining inciinntions.

What I claim as my invention, and desire to secure by Letters Patent, is-

The semicircular spirit-block E, fitting and adjustingin the semieircnlar space in the stock A, arranged and operatingjl substantially as and for the purpose herein specified.

I also claim the grooves g and 2, und stops t and l, combined and arranged substantially ns and for the purpose set 'hrth.

The above specification of my improved plumb and level signed by me, this twenty-second day of June, 1867.

S. A. BOSTWICK.

Witnesses:4

E. A. Hmmm), A. C. LEAVITI 

